A variable-pitch racked bar, as disclosed in Japanese examined and published patent application No. 52-29049, has a variable-pitch tooth profile or VGR tooth profile, in which the pitch gradually increases or decreases along a row of rack teeth. In a first arrangement, the pitch of the middle teeth is set at a minimum and the pitch is gradually increased from the middle teeth toward both ends of the row of rack teeth. This variable-pitch enhances a steering response during slalom racing, for example. In a second arrangement, the pitch of the middle teeth is set at a maximum and the pitch is gradually decreased from the middle teeth toward both ends of the row of rack teeth. This variable-pitch reduces a steering force when a steering angle is large.
The VGR tooth profile of the variable-pitch racked bar is formed by complicatedly curved tooth faces which mesh with a helical pinion provided with an involute curve. During the manufacture of the variable-pitch racked bars, the curvature of each rack tooth face unavoidably, slightly deviates from the originally designed curvature. These deviations adversely affect the meshing condition of the helical pinion in each rack tooth, causing torque variances and increasing play in the steering operation.